Reaping machines with a rotating sickle bar, on whose ends reaping blades are attached so that they can pivot, are known in the prior art and are used in the agricultural industry for reaping grass or other stalk-like crop. The reaping blades are supported so that they can pivot by means of a holding pin such that the reaping blades can be oriented radial to the rotational axis of the sickle bar by centrifugal forces generated during the rotation of the sickle bar. The holding pins are provided with a shoulder for the pivoting support of the reaping blade and have a fastening shaft that is provided with a thread and can be connected or screwed to the sickle bar. For this purpose, the holding pins are guided through a fastening hole on the end of the sickle bar and connected to the sickle bar by means of a threaded nut. To be able to withstand the stresses during reaping and to prevent detachment of the threaded connections due to vibration and pin rotation, the holding pins must be fastened with a correspondingly high tightening torque for the threaded nut. This requires special tools, in particular a torque wrench or the like, and a corresponding expense of energy. If the reaping blade must be replaced due to use and wear or in the event of damage to the reaping blade, it is often necessary to replace or exchange the blade on site or in the field. Thus, the wish of every user is to keep the mentioned maintenance expense low, to reduce the expenditure of force necessary for replacing the reaping blade, and, in particular, to not require the use of special tools.